Method of uniting metal surfaces



; Patented, May-'21, 1.19.40 ,2;

i M J Young, Iletroit, Mich. H I [I jnt 'ii iib ii oj tdti ez, jiasaf se ialgno. 236,587. tICIaims'. Cl. 10-'- 86) The present mvention relates to a metlflod'oi' v I N h completion of the operationshown in g. 8.

uniting metal surfaces such; for; example: s v

. steel surfacesziIn .a .pr eferred;embod men gh c ,7 v v F away] sho mg a completed nut embodyingfthe disclosed bywaypf example but notjof limitation, the method is i applied- ;in 1 connection with c the: formation of a ,nut which; maybe; iorrneri as taught:- in :;the-: co,-pending.;-; Oldh'am; appliq iO Serial No. ;212,532, which isxassigned --to;me, A V .Itzis-anzobjectof the present -inyenton to. provideamethodufor mechanically uniting adjacent Lportionsv .of- ;two relativelyhard :metal surfaces andia'body pf; relativelysoiter. :metalby the application:ofvrmechanical pressures thereto. 7 Another object of the; invention is to provide a method of :uniting adjacent portions .oi;.metal 1 surfaces :andmf providing a du tfl i 't coatingthereon. W V

Other objects of this inventionfyyill appearjin the 'following description and appended claims, reference beingnhad to; the accompanying, drawing forming a part of this specification wherein I like referenceflcharacters designate corresponding parts in the. several -view,s.wy a r i The drawingin the-present pplication correspends in general to the drawing appearing in ithe said. co-pending Oldham application Serial ,7

No. 212,532, ,inwhich is disclosedjthe Method of forming awheelnutfrom a metal blank; and

illustrates the applicationv of the I present inven- 30. "tion thereto-for the purp se of-.'joinin g the adjacent portions of the metal blank.

Fig." .1 is a fragmentary ,side'eleyation of; a I i v v j Referring tofthe drawing, theblanlsisfiiormed from a roundmetalstockll,such for examme metal blank; which-pmay .be used to fabricate a nut ."in which*the present methodof uniting the 5 adjacent portions-of the metal; surfaces is em- =ployed. "1.3 1. r

' Fig. 2 is acrossfsectiontaken; substantially on the lineI-l-of vFig. 1 in the direction of.,the

arrows.- e

40 Fig.3 is aview similar was; i ut's o' m a. further step in the formation of .the metal 7 .blank inwhich the circular blank of Fig. 1 has been flattened.

' {a J s. -sectiim takeni substantially 5 M Fig. 6.is a persp ctiveview of the flat ,bla'nk of H jthe to guelfi and,thegrooyejl'LfTheSeend v ,j sections 'may be copper platedprior; to the formmg "'ofjthe blankg'l 5mm the cylindrical mam;

showing) furtherZJoIaerationsfj in the jormation of a.

nu in which 55 the method herein disclosed.

the metal'surfaces are by g..9, is a sectional i of the 'the gs-.10 is a perspective yiewl withl parts broken the invention f r funitingthe 5 adjace -m ta riac giaf Y Before explaining in detail; the presentinvem tion it is to be understoodthat the; mv n'n n; is 1 not limitedin its application to. the details of .construotion'.and arrangement 'of lparts illustrated l0 mine accompanying draw ng; since the inven- 1 tion is, capable oi. other embodiments and of being H practiced or carried outin various ways? Also it is to ,beundersto'od that the phraseologyortermi- 'nology employed hereinisfor thepur'pose'of de- 15 f scriptionand @not 'ffof ,Tlimitatiom' I and it is .not

intended limit the invent on"naimeainerem beyondthehrequirements of the prior art .j 4 vs While 1 h 've chosen theiormationloff'aiwheel f'nutlas an example of one embodiment of the 20 invention-it is to 'beunderstood that the in'y'enndn is not limitedfthereto butis. applicable broadly to the unitinglof any adjacentmetallvsuriacesby the, application of mechanical pressuresv thereto.

. .A wheelnut' with whichthe'present'invention 25 is here shown issubjected to rigoroususe andgthe exposed {surfaces thereof. must be protected againstdeter'iorationdue to rust; corrosion"; etc.

, The present invention provides'a method of uniti sin'g thejadiacer'itsurfacesof themetal' blankused in formingj'the 'nut, as Well; a, at thelsairie time providing aIrlistprootcoveringthereon. j I] as an iron or steel rod orwire. This wire isprefv. eramyjrbrmedwjith a; coating IZY of cop erjor jcated generally at [5. The flat section is then [cut as shown in Fig. '5injsuch a. manner jas to,

provide a tongue Iii in, one end of each section and a; matingggrooye H in the opposite" end 4 fthereof." ira' 'men arr lan wisho ngtne c c blank has; a mat ng bfthe material 12 "'on'the faces thereof butjdoes not'haye Such a platingfon' At theconclusion of the steps in Fig. 5g-the "l8""shownin Fig. 6 if itisjdesired to connect" the ends of the blank solely by the application of mechanical pressures thereto. As there shown, the tongue I 6 mates in the groove l1 and an intermediate layer l9, preferably of copper or similar ductile metal, is inserted between the two ends of the blank l8. As previously stated, this may be accomplished by plating the respective ends of the blank after the cutting operation or it may be done by inserting a thin sheet of copper or similar material during the formation of the cylindrical blank shown in Fig. 6.

If desired, the placing of copper or other ductile metal either as a plating or as a thin sheet adjacent the ends of the blank may be dispensed with and the parts connected by the application of mechanical pressures thereto and a subsequent heating in a hydrogen furnace whereby copper from the surface flows into the mechanical joint and welds or brazes the joint.

If desired, the steps in the formation of the blank in Figs. 1 to 5, may be dispensed with and the metal may be formed from a cut blank of sheet stock. The sheet stock may be copper plated either before or after the cutting operation. The copper plating of the round stock may be as shown in Figs. 1 to 5 inclusive, or the plating may be all done after the formation of the blank 15. In any event, the cylindrical blank as shown in Fig. 6 will be provided with a surface covering of the ductile metal such, for example, as copper, and will be provided with a layer of such metal between the adjacent ends of the surfaces to be united if the union is to be effected without heatmg.

The cylindrical blank is then subjected to an upsetting operation as shown in Fig. '7, in which a punch member exerts pressure on the blank l8 and causes it to be pressed to conform to the opening in the female die member 2|. This forms the exterior contour of the object such, for example, as the wheel nut, and causes the ferrous metal and the ductile covering i2 to cold flow in the manner shown. The tongue l6 and the mating groove I! are elongated and the adjacent mating surfaces are rendered irregular. This causes the copper or similar metal IE! to flow into the irregular pattern of the adjacent faces of the tongue l6 and the groove l1 and unites the surfaces. The copper in effect impregnates the ferrous material due to the application of pressure in the upsetting operation shown diagrammatically in Fig. 7. The metal forms what in effect is a homogeneous mass, although the copper may still be separated from the body of the ferrous metal. The copper by the operation appears to be forced into the pores and surface irregularities of the surfaces of the ferrous metal. This effects an intimate engagement between the metal surfaces and the copper in much the same manner as when heat is aprlied to the copper and it is applied to such surfaces in a melted condition.

In order to remove excess metal which has flowed to the interior of the nut blank, a shearing punch 22, as shown diagrammatically in Fig. 8, may be employed to punch out the center of the nut blank l8 and cause the blank to assume the contour shown in Fig. 9. The interior of the nut may then be threaded as at 24 and the completed nut will then appear as shown in Fig. 10. As there shown, it will be seen that the nut has a covering l2 of the non-oxidizing, non-corrodible ductile metal such, for example, as copper and that the tongue l6 and the mating groove ll serve to unite the two ends of the metal blank. The copper or ductile metal I9 occupies a position between the adjacent ends of the blank and serves as a uniting material which holds the parts firmly together.

In the embodiment of the invention shown in Fig. 10, the interior threads 24 are not copper plated. In an embodiment where copper plating of the threads is desired, this may be done after the nut is formed. Any other desired type of plating or rust-proofing treatment also may be employed.

The present method of uniting the metal surfaces, it will be seen, provides a union between the adjoining metal surfaces, which union is maintained by the flow of the deformable metal in response to the pressures applied to the blank during the upsetting operation. There is no welding of the parts in the conventional sense of the term as the action of the ductile metal is to form a mechanical union between the adjacent surfaces of the other metal. The upsetting operation provides a coined surface on the outer surfaces of the metal and serves to provide a highly polished surface thereon.

I claim:

1. The method of forming a nut from relatively flat stock having a core of relatively hard metal and a covering of relatively softer and more duetile metal by the application of mechanical pressures, which comprises forming a generally cylindrical blank from said flat stock, and upsetting said blank whereby the blank is permanently changed in form with the ends thereof anchored in a layer of said relatively softer and more duetile metal and the exposed surfaces covered with said relatively softer and more ductile metal.

2. The method of forming a nut from relatively flat stock having a core of relatively hard metal and a covering of a relatively softer and more ductile metal by' the application of mechanical pressures, which comprises forming a' terior of the formed blank.

3. The method of forming a nut from relatively fiat stock having a core of relatively hard metal and a covering of a relatively softer and more ductile metal by the application of mechanical pressures, which comprises forming a generally cylindrical blank from said flat stock, upsetting said blank whereby the blank. is permanently changed in form with the ends thereof anchored in a layer of said relatively softer metal, and thereafter subjecting the formed blank to heat to cause some of the relatively softer covering metal to flow into the mechanically formed joint between the anchored ends of the blank.

4. The method of forming a nut or similar annular metal article from fiat stock, comprising the steps of forming a generally cylindrical blank from a sheet of relatively hard metal provided with a covering of a relatively softer and more ductile metal by the application of mechanical pressures thereto, and thereafter upsetting said blank whereby the blank is permanently changed in form and the ends thereof are anchored in a with a covering of a relatively softer and more ductile metal by the application of mechanical pressures thereto, and thereafter upsetting said blank whereby the blank is permanently changed in form due to the application of mechanical pressures of sufficient magnitude to cause the metal of said blank to cold flow and anchor the ends thereof in a layer of said relatively softer :znri more ductile metal.

6. The method of forming a nut or similar annular metal article from flat stock, comprising the steps of forming a generally cylindrical blank from a sheet of relatively hard metal provided with a covering of a relatively softer and more ductile metal by the application of mechanical pressures thereto, and thereafter upsetting said 5 

